<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>JS基础语法</title>
</head>
<body>
  <script>
    //1. 写入浏览器德body区域
    doucument.write("Hello JS world");
    //2. 弹出警告框
    alert("Hello JS world");
    //3. 控制台
    console.log("Hello JS world");
  </script>
</body>
</html>
